It is important to appropriately waterproof wet areas, such as a shower recess, to avoid water penetrating behind or under wall cladding or flooring. If not adequately waterproofed the wall cladding, such as plasterboard, can retain moisture and swell dislodging exposed floor or wall tiles. The most common technique to address this potential problem involves the application of a waterproof membrane to vulnerable wet areas. Generally a flexible sealant is also used in corner regions inside the waterproof membrane and around where the plasterboard wall adjoins the floor. Rigid flashing may also be used to supplement the waterproof membrane and the flexible sealant where the flashing sits in behind the plasterboard wall. These forms of waterproofing are applied prior to laying of a mortar bed and tiling of the wet area.